GB898529A - Improvements in or relating to monoazo dyestuffs and their metal complex compounds - Google Patents

Abstract

The invention comprises dyes of formula <FORM:0898529/IV (c)/1> which is the enolised form of an a -ketohydrazone made by condensing an o-diketone with an appropriate phenylhydrazine and where X is a substituent capable of taking part in metal complex formation or capable of being converted to a metallisable group during metallisatio-and A may be substituted but not with sulphonic acid groups or carboxylic acid groups directly attached to the nucleus other than in the o-position to the hydrazino group. The invention includes the metal complexes of above dyes. Preferably the dyes contain an alkyl-sulphonyl or sulphonamide group. Other specified substituents are chlorine, methyl, nitro and acetylamino groups. Representative of specified alkyl sulphonyl and sulphonamide groups are sulphonamide, sulphur-methyl, -di-methyl-, -di-(21-hydroxyethyl) -, - (21 - hydroxypropyl) -, - (31 - methoxypropyl)-, -phenyl-, -chlorophenyl- and -(21-carboxyphenyl)-amides and methylsulphonyl. Specified o-diketones are 1,2-benzo- and -naphthoquinones, 9,10-phenanthrenequinone, isatin, acenaphthenequinone, dibromisatin, N-methylisation and N-acetylisatin. Condensation is preferably effected in a strongly aqueous acid medium. Chromium and cobalt are preferred metals, 1,2-complexes are preferred. Metallisation may be effected in substance or on the fibre. The dyes colour wool by the one bath chrome process and their metal complexes colour wool, silk, leather and polyamide fibres. They may also be used for mass dyeing of plastics and lacquers. Examples and a table are provided illustrating the preparation of the dyes and their metal complexes and the use of the latter in dyeing wool in a variety of shades. In Example 2 silk and polyamide fibres and leather are dyed in a green shade.